Active Directory Auditor: how to protect identities and access

Sooner or later, every access to a file, a shared folder or a business application goes through Active Directory.

That’s why monitoring it is no longer a task reserved for system administrators. It has become a cornerstone of every company’s cybersecurity strategy.

In this article, we look at what an Active Directory Auditor is, how it works, what benefits it delivers and why SGBox’s permission analysis for Windows file servers marks a step forward in access management and monitoring.

Microsoft Active Directory: the heart of corporate identity

Active Directory (AD) is Microsoft’s directory service for managing identities and permissions in Windows environments.

Think of it as the “central registry” that defines who each user is, which groups they belong to and which resources they can access.

Active Directory is responsible for:

• authenticating users and computers to the domain;
• assigning permissions through security groups;
• enforcing policies through Group Policy Objects (GPOs);
• granting access to resources such as file servers, shared folders, printers and integrated applications.

Why is Active Directory a prime target?

Precisely because it holds the keys to access, Active Directory is one of the first things attackers go after.

Compromising a single highly privileged account can mean gaining access to most of the files and folders across the corporate network.

But the risk doesn’t only come from outside. Over the years, Active Directory builds up inactive accounts, nested groups, forgotten delegations and “temporary” permissions that nobody ever reviews again.

What is an MS Active Directory Auditor?

An Active Directory Auditor is a solution that collects, analyses and retains information about Active Directory objects, configurations and changes.

Its goal is to identify risks, anomalies and security policy violations before they turn into incidents.

Windows already records many events in its security logs, but they are spread across multiple servers, hard to read and kept for a limited time.

An auditor centralises them and adds context: who did what, when, from where and with what impact.

What does an Active Directory Auditor monitor?

• Users: creation, deletion, re-enabling and password resets, plus inactive accounts or accounts with passwords that never expire.
• Groups: members added or removed, with a particular focus on privileged groups such as Domain Admins, Enterprise Admins and Administrators.
• Privileges and delegations: administrative rights assigned to users, groups or service accounts.
• Policies and configurations: changes to GPOs and to directory object attributes.
• Authentication: successful and failed logons, account lockouts, logons at unusual times or from unusual devices.
• File access: reads, changes, deletions and permission changes on files and shared folders.

How an Active Directory Auditor works: the process

The way an Active Directory Auditor works can be summed up in six stages, which turn scattered technical events into actionable security insight.

1. Data collection

The auditor gathers events from the security logs of domain controllers, servers and workstations, together with the state of directory objects and, in the most advanced solutions, file server ACLs.

2. Normalisation and baseline

Events are converted into a common format and compared against a reference “snapshot” of the environment. This is how the system tells what is normal from what is an anomaly.

3. Risk analysis and KPIs

Configurations and changes are assessed against risk indicators: number of administrators, inactive accounts, excessive permissions, passwords that never expire. When a KPI exceeds its threshold, the system raises an alert.

4. Correlation and alerts

Active Directory events are correlated with other security sources. A single failed logon is no cause for concern. Dozens of attempts followed by a successful logon and the addition to a privileged group tell a very different story.

5. Reporting and retention

Scheduled reports and dashboards make the data accessible to IT, security and compliance teams. Historical retention makes it possible to reconstruct events even months later.

6. Response and remediation

The information collected drives corrective action: revoking a privilege, disabling an account, restoring a configuration or launching an investigation.

What are the benefits of implementing an Active Directory Audit system?

An Active Directory audit system lets you see in real time who is accessing what, spot privilege abuse and risky configurations, and demonstrate regulatory compliance with objective data. In practice:

• Early threat detection: anomalous movements, privilege escalation and compromised accounts surface before the attack reaches your data.
• Privilege control: you can enforce the principle of least privilege and verify it over time.
• Reduced attack surface: inactive, orphaned or over-privileged accounts are identified and cleaned up.
• Faster forensic investigations: the change history lets you reconstruct the sequence of events in minutes, not days.
• Demonstrable compliance: reports and traceability support NIS2 and GDPR audits.
• Operational efficiency: automated analysis and reporting replace lengthy, error-prone manual checks.

What the ENISA Threat Landscape 2026 data shows

The latest report from the European Union Agency for Cybersecurity analysed 8,257 incidents that took place in 2025. Several findings confirm just how central identities, access and configurations are:

• unauthorised access is the second most frequent incident type, accounting for 5% of the total;
• 9% of unauthorised access incidents are financially motivated;
• among unauthorised access incidents where the intrusion vector was identified, 7% are linked to misconfigurations and accidental exposure, while 60.4% exploit vulnerabilities;
• the share of unauthorised access attributable to insider threats has grown compared to the previous year;
• infostealers continue to harvest credentials, MFA tokens and session cookies, enabling account takeover and unauthorised access;
• the techniques most used by the leading ransomware groups active in the EU include the use of valid accounts (MITRE T1078) and network share discovery (T1135).

These figures show that only continuous analysis of identities, access and privileges makes it possible to spot an anomaly or suspicious behaviour tied to an access.

The Importance of access control and File Integrity

Active Directory says who you are. File system permissions say what you can change. And that’s where contracts, customer data, projects and intellectual property live.

ENISA highlights this too: among the techniques of the leading ransomware operators, data exfiltration (73.3%) far outweighs encryption (13.7%).

This signals a shift from attacks built on locking systems to data theft and extortion. It also shows that protecting file servers means protecting what the attacker is really after.

Privilege creep: a risk that builds up over time

The problem is rarely the initial access. It’s the way privileges pile up over the years without ever being revoked:

• onboarding: the user receives baseline permissions;
• department change: new permissions are added on top of the old ones;
• special project: “temporary” administrative rights are granted;
• hidden vulnerability: nobody notices, until the account is compromised.

Risky configurations to watch out for

• Permissions granted to very broad groups such as Everyone, Domain Users or Authenticated Users;
• Full Control given to users who don’t need it;
• Broken inheritance on folders, which then slip outside central policies;
• Orphaned SIDs (ghost accounts), i.e. permissions still tied to accounts that no longer exist in AD;
• Unjustified ownership changes on files and folders.

Integrity: knowing what changed, not just what it looks like today

A static analysis shows the current state of permissions. But when an incident occurs, the real question is different: what changed, when, and who did it?

ENISA identified 33 European organisations that were hit more than once during the same period. It considers it likely that repeat victimisation was enabled by a lack of restoration practices following incident response.

Verifying the integrity of permissions and configurations after an attack is an essential part of remediation.

The link with the NIS2 Directive

According to ENISA, essential and important entities account for around 73% of the events recorded in 2025. Article 21 of the NIS2 Directive lists access control policies and asset management among its cybersecurity risk-management measures.

An audit system covering Active Directory and file servers helps provide evidence of these controls, continuously and in a documented way.

SGBox MS Active Directory Auditor: from identities to File Security Intelligence

SGBox MS Active Directory Auditor (ADA) is the SGBox platform module designed to constantly monitor the status of Active Directory, determine the level of risk and warn you when set KPI thresholds are exceeded.

Its features are built on three pillars:

• Advanced control: helps organisations meet data protection requirements through oversight of MS Active Directory.
• Full visibility: provides a clear picture of all changes to AD resources, including objects and their attributes.
• Immediate response: helps detect insider threats, privilege misuse and indicators of compromise.

ADA integrates with the other SGBox modules and generates lists that can be used for event correlation and detailed reporting.

Rounding out these capabilities is the Windows File System Auditor, which monitors file and folder operations (creation, deletion, modification and read), with dedicated correlation rules and scheduled reports.

Active Directory, Auditing, File Security, Compliance and native SIEM: one technology

The Active Directory Auditor is integrated with the SGBox SIEM. It turns permission data into contextualised insight that improves governance, strengthens the principle of least privilege and makes it easier to demonstrate regulatory compliance.

• Active Directory defines identities and groups;
• Auditing tracks changes, access and privileges;
• File security reveals who can actually reach critical data;
• Compliance relies on continuous evidence, not one-off checks;
• The SIEM correlates everything in real time and speeds up response.

Picture a real-world scenario: the SGBox SIEM detects an anomalous logon to an administrative user’s account, outside working hours and from an unusual device.

Thanks to ADA, the security team can immediately see which folders that account can reach (HR, Finance, R&D) and whether its permissions have changed recently.

This way, permission data stops being a simple list and becomes immediate context to detect and neutralise threats before they cause damage.